An apparatus using Composite Video Blanking and Sync (CVBS) signals, such as a Digital Video Disk (DVD), a low-performance camera device, and the like, is still widely used due to the low cost thereof. At present, a piece of video formed by interlaced scanning CVBS signals needs to be processed by deinterlace algorithm before it is outputted to a progressively scanning display device. When using the deinterlace algorithm, important information that whether field is an odd field formed by odd-numbered rows or an even field formed by even-numbered rows needs to be provided.
However, some of advanced image processing chips can only process high-definition and progressively scanning videos, and cannot provide the functions of interlaced scanning videos processing, odd-even field identification, and deinterlace processing. In fact, odd-even field information in the CVBS signals will be discarded by the advanced image processing chips of this type. In order to further reduce cost, a CVBS source video signal may be used, and the advanced image processing chips aforesaid may be used subsequently.
However, as is mentioned above, the advanced image processing chips aforesaid cannot provide a function of odd-even field identification, and will discard the odd-even field information in the CVBS signals. Furthermore, data acquired by the advanced image processing chips is in field, rather than in frame. That is, the image data each time acquired includes the field containing all the odd-numbered rows or the field containing all the even-numbered rows; however, the odd-even feature of the data of each field cannot be identified by the advanced image processing chips. Meanwhile, for the sake of reducing cost, as is mentioned above, the advanced image processing chips used can provide neither the function of deinterlace processing, nor the function of odd/even field identification; in this way, after acquiring the image date from the advanced image processing chips, software is needed to perform the deinterlace processing, and thus the odd-even field information should be identified from the image data.
When the odd-even field information provided in the CVBS signals is identified, deinterlaced and synthesized into an integrated frame of image by specialized hardware, the cost of the specialized hardware is fairly high as a result. Furthermore, it is possible for the field to be discarded by the image processing chips, and thus the time correlation of the odd-even field may be disordered, and errors may occur in the field sequence. In lots of solutions, the field sequence is preset at the beginning of video playing; however, when the deinterlace processing is performed in this mode all the time, visibly jaggies will be produced in the processed images, and the self-adaptive adjustment cannot be achieved, resulting in a poor processing effect. In this case, the setting of the odd-even field used before will be failed, and thus it needs to detect in real time whether this specific case happens, and correct the errors in time.
In addition, the solutions using an input in field generally adopt the intensive analysis, and can acquire the results only after the processes of the whole video are finished. Therefore, when using these solutions, a large calculation amount is involved, thereby prolonging the processing time, which cannot meet the requirement of real-time identification.